Disinfecting method for disinfecting a room or surface, and disinfecting fluid composition suitable for transforming into an aerosol of fluid particles suspended in a gas

ABSTRACT

Disinfecting method for disinfecting a room or a surface, comprising the steps of: a) providing a fluid comprising at least one organic compound obtainable from natural substances, wherein the organic compound is provided in an non-polar or polar medium, or in a mixture of non-polar and polar media; b) mixing the fluid with a gas such that fluid particles are suspended in the gas, and an aerosol of fluid particles is formed; c) directing a flow of the aerosol formed in step b) on said surface or into said room.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a National Phase application claiming priority toPCT/EP2012/063401 filed Jul. 9, 2012 which claims priority to NL 2007071filed Jul. 8, 2011, all of which are herein incorporated by reference intheir entireties.

The present invention is related to a disinfecting method fordisinfecting a room or a surface, wherein a flow of an aerosol is usedas a disinfectant.

A disinfecting method is in general aimed at inactivatingmicroorganisms, for sanitary reasons.

It is further known to use an aerosol as a disinfectant and to apply aflow of aerosol through a room or onto a surface that should bedisinfected. Thus, a room containing airborne microorganisms can besanitized. Alternatively, a surface on which microorganisms are presentcan be sanitized. In both ways, any confined space designed for humansor animals can be sanitized in order to reduce or eliminate the risk ofinfection by microorganisms.

Most known disinfectants are however potentially harmful to humans oranimals, and require a careful use thereof as well as additional safetymeasures before a sanitized space is used by humans or animals. Thisdrawback is even more prominent, when the disinfectant is used in theform of an aerosol, because any unwanted absorption by a living creature(through the skin or through the respiratory tract) is more prone tooccur, when compared to a disinfectant that is used in liquid form.

Furthermore, using an aerosol for disinfecting purposes has been foundto be less effective in case the suspended particles in the aerosol havea particle size with a broad size distribution, i.e. the particleshaving a large variation in particle size.

The invention is aimed at reducing or eliminating the above drawbacks.

In addition, an attractive way of disinfecting confined spaces in whichanimals are kept, could significantly reduce the need for treatinganimals with antibiotics.

Further, the disinfected method is also aimed at sanitizing rooms whichare used by humans, such as hospital rooms, the interior of aeroplanes,etc.

Therefore, the invention relates, according to a first aspect thereof,to a disinfecting method for disinfecting a room or a surface,comprising the steps of:

a) providing a fluid comprising at least one organic compound obtainablefrom natural substances, wherein the organic compound is provided in annon-polar or polar medium, or in a mixture of non-polar and polar media;

b) mixing the fluid with a gas such that finely divided particles offluid are suspended in the gas, and consequently an aerosol of thesuspended fluid particles is formed;

c) directing a flow of the aerosol formed in step b) on said surface orinto said room.

The above method is advantageous over the prior art, because it makesuse of an organic compound obtainable from natural substances, whichcompound has a reduced toxicity compared to known disinfectants, whileat the same time being effective as a disinfectant when applied in theform of an aerosol. The organic compounds in the form of suspendedparticles of an aerosol are much better characterized than particles ofthese organic compounds used in traditional disinfection methods thatare, for example, based on vaporisation of these organic substances.Thus, the wished (disinfection) effect can be induced much better and,particularly, in a quantitative way. Hence, if the disinfection methodaccording to the present invention is used to disinfect confined spacesin which animals are kept, especially stables, the need for treatinganimals with antibiotics can significantly be reduced and, in turn,problems with residues of such antibiotics can be diminished or evenavoided.

The non-polar medium can be an oil, preferably olive oil, and polarmedium can be water, preferably water containing dissolved salts. Forinstance, the water may contain dissolved calcium hydroxide or sodiumchloride, i.e. the water may be lime water or saline. Other usefuldissolved salts are sea salts and sulphur salts.

Preferably, the overall ratio in the fluid between the total ofnon-polar compounds and the total of polar compounds, is between 4:1 to1:4, more preferably between 2:1 to 1:2.

Typically, the aerosol used in the disinfecting method could be based ona fluid content of 0.1 to 15 ml fluid per cubic meter gas; for instancea fluid content of 1.0 to 3 ml fluid per cubic meter gas is used in themethod.

Preferably, in the method of the invention and subsequent to step b) andprior to step c), the fluid particles of the aerosol of which the meanparticle size is 1 micrometer or above, are separated from the aerosol.

The aerosol formed in step b) contains fluid particles having a broadsize distribution which ranges from some nanometers to severalmicrometers. It has been found that in step c), wherein the aerosol isapplied as a disinfectant, it is advantageous to apply an aerosol whichcontains particles having a mean particle size below 1 micrometer.Especially the range of a mean particle size between 10 and 100nanometer was found to improve the effectiveness of the aerosol as adisinfectant.

Any known separation method for the aerosol may be applied, such asfiltration. Another separation method, is based on the insight that whenleading a flow of aerosol over deflecting surfaces, the larger particles(i.e. larger than 1 micrometer) could be separated from the smallerparticles.

Separating the larger particles makes the size distribution of theremaining smaller particles narrower—the aerosol is bettercharacterized. This in turn reduces irritation effects that might occurwhen less-characterized particles with a larger size distribution areused for disinfection, particularly for disinfection of confined spacesin which animals are kept. I.e. in the latter case, thewell-characterized aerosol with the narrow size distribution reducespossible irritations of the animals.

Another advantage of the narrow size distribution is that depositedmasses can be calculated very accurately. This enables one to preciselyuse only the necessary—and thus very limited—amount of particles fordisinfection. In case of disinfection of the air in confined spaces inwhich animals are kept, especially in case of disinfection of the air instables, the limited amount of particles further helps to avoidirritations of the animals.

Advantageously, in the method of the invention, the separated fluidparticles of the aerosol are returned to the fluid that is used in stepb). As such, the fluid particles which are too large for thedisinfecting method, are recycled so that no fluid is lost in theprocess.

Preferably, in step a) of the disinfecting method of the invention, theat least one organic compound is chosen from the group consisting of:azulene, the essential oil of thyme, the essential oil of cloves, aresin from plants, derivates of the above organic compounds, andmixtures of the above organic compounds.

Azulene is a compound obtained from the distillate of camomile. Theessential oils indicated above, refer to the oily substance that can bedirectly obtained from thyme and cloves, either by extraction ordistillation processes. The resin from plants is meant as the viscoussubstance that is obtained from the stems of plants. A particular usefulresin for the invention is Frankincense (also referred to as Olibanum)which is the aromatic resin obtained from the tree Boswellia.

With special preference, in step a) of the disinfecting method of theinvention,

-   -   the at least one organic compound is provided in a mixture of a        non-polar and a polar medium, wherein        the non-polar medium is an oil, preferably olive oil, and polar        medium is water, preferably water containing dissolved salts.        For instance, the water may contain dissolved calcium hydroxide        or sodium chloride, i.e. the water may be lime water or saline.        Other useful dissolved salts are sea salts and sulphur salts.

It was found that when the organic compound is provided in the abovetype of medium, the disinfecting effect is further enhanced.

Furthermore, it was found advantageous that in step a) of thedisinfecting method of the invention,

-   -   the fluid provided comprises an organic compound in water, the        organic compound being present in an amount of 5-50 wt. %,        preferably 10-30 wt. %, of the fluid.

The above range for the content of organic compound in the fluid, wasfound to be an effective concentration when used in the disinfectingmethod. The same favourable range is applicable to a mixture of organiccompounds is used, wherein each organic compound is present in an amountof 5-50 wt. %, preferably 10-30 wt. %, of the fluid.

Especially preferred in the disinfecting method of the invention, is touse a mixture of organic compounds in water which comprises azulene, theessential oil of thyme, and the essential oil of cloves.

It was found that when applying an aerosol based on this specificmixture of organic compounds in accordance with the method of theinvention, it was possible to achieve a high disinfecting effect. Morespecifically, it was found possible to reduce the amount ofmicroorganisms that are suspended in the air of a confined room by 80%or more. This reduced amount of microorganisms was measured 36 hoursafter leading a flow of the aerosol into the confined room according tothe invention.

Furthermore, it was found that the disinfecting effect of the methodcould be further enhanced by including a resin from plants as an organiccompound in the fluid composition. A particular useful resin for theinvention is Frankincense (also referred to as Olibanum) which is thearomatic resin obtained from the tree Boswellia.

According to another preferred variant of the disinfecting method of theinvention, in step b), a mixture of the fluid and the gas is led underpressure through a nozzle, so that a spray of aerosol is discharged fromthe nozzle.

The use of a nozzle to form an aerosol was found both expedient andeffective for the method of the invention.

In a specific variant of the disinfecting method of the invention, instep b), the gas is led under pressure through a nozzle and the fluid isadmixed to the gas during passage through the nozzle, so that a spray ofaerosol is discharged from the nozzle.

Such a method makes use of the Venturi-effect inside the nozzle, whereinthe constricted flow of gas through the nozzle has a higher velocitywhich results in a reduced pressure. The reduced pressure is theneffective for drawing in the fluid into the flow of gas, so that thefluid can be admixed to the gas stream, simply by providing a separateconduit for fluid which exits inside the nozzle.

When using a nozzle to form an aerosol according to the method of theinvention, it is preferable that subsequent to step b) and prior to stepc), the fluid particles of the aerosol of which the mean particle sizeis 1 micrometer or above, are separated from the aerosol by directingthe spray of aerosol into a mixing chamber in which the spray isdeflected by deflecting surfaces, and from which mixing chamber theaerosol is discharged via an outlet in order to perform step c).

As already explained above, the deflecting surfaces were found to behighly effective in separating larger particles (having a mean size of 1micrometer or more) from the aerosol, which enhances the disinfectingefficacy of the method.

In a further variant of the disinfecting method of the invention, themixing chamber and the nozzle are assembled in the form of a cartridgewhich further comprises a reservoir for the fluid which is in fluidcommunication with the nozzle and the mixing chamber. As such, thecartridge combines three functionalities needed in the method of theinvention: i) the mixing of fluid and gas into an aerosol, ii) theseparation of larger particles from the aerosol, iii) a reservoir forfluid to which separated particles are returned.

In a final variant of the disinfecting method of the invention, thecartridge further comprises an inlet for supplying fluid to thereservoir from a source outside of the cartridge.

As such, a disinfecting method is provided wherein a non-limited amountof fluid can be used. This is advantageous especially when large roomsare to be disinfected, and wherein the reservoir of the cartridge itselfmay not have the capacity for discharging the required amount of fluid.

According to a second aspect, the invention relates to a disinfectingfluid composition suitable for transforming into an aerosol of fluidparticles suspended in a gas, comprising:

-   -   at least one organic compound obtainable from natural        substances, which organic compound is present in a non-polar or        polar medium, or in a mixture of non-polar and polar media,    -   and wherein the at least one organic compound is chosen from the        group consisting of: azulene (i.e. a distillate from camomile),        the essential oil of thyme, the essential oil of cloves, a resin        from plants, derivates of the above organic compounds, and        mixtures of the above organic compounds.

A particular useful resin for the invention is Frankincense (alsoreferred to as Olibanum) which is the aromatic resin obtained from thetree Boswellia.

When such a fluid composition is used in the disinfecting method asdescribed above, the same advantages are achieved as already indicated:in particular, a large reduction of microorganisms in a room treated bythe method of the invention is achieved.

Preferably, the disinfecting fluid composition of the invention fulfilsthe condition that:

-   -   the at least one organic compound is provided in a mixture of a        non-polar and a polar medium, wherein        the non-polar medium is an oil, preferably olive oil, and polar        medium is water, preferably water containing dissolved salts.

The related advantages have already been indicated above for the methodof the invention when it includes the same features.

According to a further preference, in the disinfecting fluid compositionof the invention, the organic compound is present in an amount of 5-50wt. %, preferably 10-30 wt. %, of the fluid composition.

When a mixture of organic compounds is used, the same preferred amountis applicable to each organic compound.

With particular preference, the fluid composition comprises a mixture ofthe organic compounds azulene, the essential oil of thyme, and theessential oil of cloves, and wherein each organic compound is present inan amount of 5-50 wt. %, preferably 10-30 wt. %, of the fluidcomposition.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further explained according to the example below,together with the appended FIGS. 1 and 2.

EXAMPLE

FIG. 1 shows a simplified view in cross-section of a cartridge to beused in the method of the invention.

FIG. 1 shows a cartridge 1 for disinfecting fluid, which has outsidewalls 2, which are penetrated by: an inlet 3 for pressurized gas from anoutside source (not depicted), an inlet 5 for disinfecting fluid from anoutside source (not depicted), and outlets 7 for discharging aerosolformed inside the cartridge 1. The cartridge 1 is of a generalcylindrical shape, with the dotted line X marking the respectivecylindrical axis. The bold arrows A mark the direction of streams of gasand aerosol within the cartridge 1.

Inside the cartridge 1, a conduit 10 for leading the introduced gas isprovided, which narrows into a nozzle 12. The conduit 12 has internalchannels 14 for leading fluid towards the nozzle 12. The channels 14 arein fluid communication with the narrow part of the nozzle passage 12, atwhich the gas passing through will exhibit a reduced pressure (i.e. theVenturi effect). Consequently, the fluid 25 kept in the lower part ofthe cartridge (i.e. the reservoir for fluid), will be drawn throughchannels 14 towards the nozzle 12 and mix with the gas, thus discharginga spray which is an aerosol of fluid particles in the gas. Opposite tothe exit side of the nozzle 12, is a deflecting structure 20 positioned,in order to deflect the spray discharged from the nozzle 12. Grace tothe deflection, a turbulent stream of aerosol is formed (depicted by thebent arrows A, which illustrate a circular flow), wherein larger fluidparticles will return to the fluid 25, while smaller fluid particles(having a mean size below 1 micrometer) will remain suspended in thegas. At the same time, the aerosol spreads out over mixing chamber 27,and the smaller particles finally exit the cartridge through outlets 7.The aerosol discharged from the outlets 7 may be directly used fordisinfecting a room or a surface by leading the flow of aerosol in anappropriate direction. The inlet 5 is used when an additional amount ofdisinfecting fluid is required inside the cartridge, so that thecapacity for discharging aerosol from the cartridge is not restricted tothe size of the reservoir inside.

FIGS. 2A and 2B show respectively a top and bottom view of the cartridgedepicted in FIG. 1. The same features as depicted in FIG. 1, areindicated by the same reference numbers.

An example of a useful fluid composition for the disinfecting method ofthe invention, contains 40 wt. % thyme oil, 50 wt. % lime water, and 10wt. % of a non-polar mixture, which includes oil of cloves, azulene andFrankincense.

Another example of a particularly useful fluid composition for thedisinfecting method of the invention contains 49 wt. % thyme oil, 50 wt.% lime water, and 1 wt. % of azulene (i.e. a distillate from camomile).

The invention claimed is:
 1. A disinfecting method for disinfecting aroom or a surface, comprising the steps of: a) providing a fluidcomprising at least one organic compound obtainable from naturalsubstances, wherein the organic compound is provided in a non-polar orpolar medium, or in a mixture of non-polar and polar media, wherein theat least one organic compound is chosen from the group consisting of:azulene, the essential oil of thyme, the essential oil of cloves, aresin from plants, derivates of the above organic compounds, andmixtures of the above organic compounds, wherein the at least oneorganic compound is provided in lime water or in a mixture of anon-polar medium and lime water, wherein the organic compound is presentin an amount of 5-50 wt. % of the fluid; b) mixing the fluid with a gassuch that fluid particles are suspended in the gas, and an aerosol offluid particles is formed; c) directing a flow of the aerosol formed instep b) on said surface or into said room.
 2. The disinfecting methodaccording to claim 1, wherein subsequent to step b) and prior to stepc), the fluid particles of the aerosol of which the mean particle sizeis 1 micrometer or above, are separated from the aerosol.
 3. Thedisinfecting method according to claim 2, wherein separated fluidparticles of the aerosol are returned to the fluid that is used in stepb).
 4. The disinfecting method according to claim 1, wherein in step a):the at least one organic compound is provided in a mixture of anon-polar medium and lime water, wherein the non-polar medium is an oil.5. The disinfecting method according to claim 1, wherein in step a): theorganic compound is present in an amount of 10-30 wt. % of the fluid. 6.The disinfecting method according to claim 1, wherein in step b): amixture of the fluid and the gas is led under pressure through a nozzle,so that a spray of aerosol is discharged from the nozzle.
 7. Thedisinfecting method according to claim 1, wherein in step b): the gas isled under pressure through a nozzle and the fluid is admixed to the gasduring passage through the nozzle, so that a spray of aerosol isdischarged from the nozzle.
 8. The disinfecting method according toclaim 6, wherein subsequent to step b) and prior to step c), the fluidparticles of the aerosol of which the mean particle size is 1 micrometeror above, are separated from the aerosol by directing the spray ofaerosol into a mixing chamber in which the spray is deflected bydeflecting surfaces, and from which mixing chamber the aerosol isdischarged via an outlet in order to perform step c).
 9. Thedisinfecting method according to claim 8, wherein the mixing chamber andthe nozzle are assembled in the form of a cartridge which furthercomprises a reservoir for the fluid which is in fluid communication withthe nozzle and the mixing chamber.
 10. The disinfecting method accordingto claim 9, wherein the cartridge comprises an inlet for supplying fluidto the reservoir from a source outside of the cartridge.
 11. Adisinfecting fluid composition, comprising: at least one organiccompound obtainable from natural substances, which organic compound ispresent in a nonpolar or polar medium, or in a mixture of non-polar andpolar media, and wherein the at least one organic compound is chosenfrom the group consisting of: azulene, the essential oil of thyme, theessential oil of cloves, a resin from plants, derivates of the aboveorganic compounds, and mixtures of the above organic compounds, whereinthe at least one organic compound is provided in lime water or in amixture of a non-polar medium and lime water, wherein the organiccompound is present in an amount of 5-50 wt. % of the fluid composition.12. The disinfecting fluid composition according to claim 11, whereinthe at least one organic compound is provided in a mixture of anon-polar medium and lime water, wherein the non-polar medium is an oil.13. The disinfecting method according to claim 7, wherein subsequent tostep b) and prior to step c), the fluid particles of the aerosol ofwhich the mean particle size is 1 micrometer or above, are separatedfrom the aerosol by directing the spray of aerosol into a mixing chamberin which the spray is deflected by deflecting surfaces, and from whichmixing chamber the aerosol is discharged via an outlet in order toperform step c).
 14. The disinfecting method according to claim 13,wherein the mixing chamber and the nozzle are assembled in the form of acartridge which further comprises a reservoir for the fluid which is influid communication with the nozzle and the mixing chamber.
 15. Thedisinfecting method according to claim 14, wherein the cartridgecomprises an inlet for supplying fluid to the reservoir from a sourceoutside of the cartridge.
 16. The disinfecting fluid compositionaccording to claim 12, wherein the non-polar medium is olive oil. 17.The disinfecting fluid composition according to claim 11, wherein theorganic compound is present in an amount of 10-30 wt. % of the fluidcomposition.
 18. The disinfecting method according to claim 4, whereinthe non-polar medium is olive oil.